From Wikipedia: "A moon dog,(scientific name paraselene... i.e. "beside the moon") is a relatively rare bright circular spot on a lunar halo caused by the refraction of moonlight by hexagonal-plate-shaped ice crystals in cirrus or cirrostratus clouds. Moon dogs appear 22° to the left and right of the moon. They are exactly analogous to sun dogs, but are rarer because to be produced the moon must be bright and therefore full or nearly full. "
We had a dog when I was growing up, Wolfie, who loved the moon. And how he would howl! Do all dogs love the moon?